Personal computers such as the IBM family of personal computers and the so-called IBM clones or compatibles are produced with an "open architecture" design for allowing additional functions to be later added to the computer. As a result, a number of manufacturers produce various printed circuit boards or "expansion cards" which are mounted in the computer for later expanding its available functions. For instance, expansion cards can be installed in the computer to provide a hard disk drive controller, a color/graphics monitor, networking, memory expansion, printer ports, accelerator functions, modems, and the like.
In order to facilitate connection of expansion cards to the computer circuitry, the computer has a number of expansion slots on the rear panel of the computer chassis. The expansion slots have separate removable cover plates for radiation shielding and for serving as dust covers for the expansion slots. These cover plates are removed when the expansion cards are added. The computer chassis typically includes a row of separate plug-in expansion card sockets at the base of the chassis inside the individual expansion slots. The cover plate over a selected expansion slot is removed and the expansion card is plugged into the socket inside the expansion slot. The expansion card has a long, narrow edge connector which projects from the bottom edge of the card and is plugged into the expansion card socket. The edge connector has a number of parallel metal plated contacts which make contact with corresponding spring-loaded contacts in the expansion card socket. The cover plate originally used for the expansion slot is usually thrown away when the expansion card is added. The old cover plate is replaced by a full-length mounting bracket fastened to the rear edge of the expansion card. This mounting bracket together with the card's connection to the socket at the base of the computer chassis provide a dual means of support at the bottom and rear edge of the card for stabilizing the expansion card (holding it in a fixed upright position) inside the unit.
The mounting bracket is a specially fabricated metal piece having a flat face to cover the expansion slot (to serve as the radiation shield and dust cover in place of the removed cover plate). The bracket also has a tab at its top for fastening to the top inside edge of the computer chassis by the screw that held the expansion slot's original cover plate in place. The manufacturer of the expansion card typically fastens the special mounting bracket to the expansion card during assembly of the expansion card. The bracket is rigidly fastened to the edge of the card by riveting or by fasteners such as screws. Thus, each expansion card is sold in combination with the special mounting bracket used to replace the original cover plate on the expansion slot where the card is plugged into the unit by the user.
The mounting bracket affixed to the expansion card may carry external plugs or adapters for connection to external communications such as a modem or a printer; or the bracket may have a plain, full length cover plate portion (without external plugs or adapters) if the expansion card is used solely for internal communications within the computer, such as for a hard disk drive controller, memory expansion and the like.
The present invention provides a simple and inexpensive means of fastening the expansion card in place inside the expansion slot of the computer with the result that labor and materials costs normally associated with providing expansion cards with expansion slot mounting brackets are greatly reduced.